1.	Measure and record the mass of the cart plus the force sensor.
2.	From the collected data, plot a force versus acceleration curve for the cart as it moves back and forth in front of the motion sensor.
3.	Find the slope of the curve. The slope of the curve is the mass of the cart plus the force sensor.
4.	Is the value of the slope from the graph equal to the mass of the cart you measured? If yes, Why?
5.	If there is any difference, try to explain the reason.